Progress Update
I've finished implementing the mock-up so that's working great now along with all the nice usability stuff. One thing I overlooked was the ability to actually create rooms so I'll need to go back and make a few extra changes to the server. After that, the last thing to do is the chat interface mock-up and code implementation.
I've been giving more thought to player-owned rooms and the volume of them and I think initially I'm going to allow anyone to create them, however rooms will be "destroyed" when the creator leaves them and everyone will get kicked out. This should keep the number of rooms down while also giving people the freedom to create them. For other usage cases such as clan rooms, there's a "persistent" flag for rooms which can be set by RTB Staff which means the room will exist permanently. I'll re-visit this after release and see how it works out.